Second edition of Space Hulk changed up some of the rules, especially regarding how the flamer works. Many the rules were over simplified over 1st edition. The space marine miniatures supplied are different than the first edtion's. These marines are more like the table top battle game's marines of the time, with crisper less simplified sculpts. Evenso, they appear less gritty than the originals. 2nd edition also incorporates the same miniature sculpts for the genestealers as first edition.